Legacy communication is mostly Human to Human (H2H) communication conducted via a Base Station (BS). Now, the development of communication technology enables M2M communication. As its appellation implies, M2M communication is communication between electronic terminals. While M2M communication means wired or wireless communication between electronic terminals or communication between a human-controlled terminal and a machine in its broadest sense, it is typical in these days that M2M communication refers to wireless communication between electronic terminals, i.e. terminals.
When the concept of M2M communication was introduced in the early 1990s, it was regarded merely as the concept of remote control or telematics and its market was very limited. However, M2M communication has been drastically developed and the M2M communication market has attracted much attention all over the world including Korea over the past few years. Especially, M2M communication has a great influence on the fields of fleet management, remote monitoring of machines and facilities, smart metering for automatically measuring the working time of construction equipment and the consumption of heat or electricity, etc. in the market of Point Of Sales (POS) and security-related applications. It is expected that M2M communication will find its various uses in conjunction with legacy mobile communication, very high-speed wireless Internet or Wireless Fidelity (WiFi), and low-output communication solutions such as Zigbee and thus will extend to Business to Customer (B2C) markets beyond Business to Business (B2B) markets.
In the era of M2M communication, every machine equipped with a Subscriber Identity Module (SIM) card can be managed and controlled remotely because it is possible to transmit data to and receive data from the machine. For example, M2M communication is applicable to a very broad range including numerous terminals and equipment such as a car, a truck, a train, a container, an automatic vending machine, a gas tank, etc.
As the application types of M2M devices have been increasing in number, a number of such M2M devices may exist in the same BS. When a huge number of M2M devices in idle state attempt network reentry, connection collisions and congestions increase, thus degrading communication performance. However, there is no specified procedure for performing network reentry in idle state by an M2M device having different characteristics from an existing terminal (H2H terminal).